package manager

import (
	"fmt"
	"strings"

	"github.com/rancher/rancher/pkg/catalog/helm"
	"github.com/rancher/types/apis/management.cattle.io/v3"
	"github.com/sirupsen/logrus"
	"gopkg.in/yaml.v2"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

func traverseFiles(repoPath string, catalog *v3.Catalog) ([]v3.Template, []string, map[string]v3.VersionCommits, []error, error) {
	logrus.Info("traversing files and generating templates")
	index, err := helm.LoadIndex(repoPath)
	if err != nil {
		return nil, nil, nil, nil, err
	}
	newHelmVersionCommits := map[string]v3.VersionCommits{}

	var templates []v3.Template
	var errors []error
	for chart, metadata := range index.IndexFile.Entries {
		newHelmVersionCommits[chart] = v3.VersionCommits{
			Value: map[string]string{},
		}
		existingHelmVersionCommits := map[string]string{}
		if catalog.Status.HelmVersionCommits[chart].Value != nil {
			existingHelmVersionCommits = catalog.Status.HelmVersionCommits[chart].Value
		}
		keywords := map[string]struct{}{}
		// comparing version commit with the previous commit to detect if a template has been changed.
		hasChanged := false
		versionNumber := 0
		for _, version := range metadata {
			newHelmVersionCommits[chart].Value[version.Version] = version.Digest
			digest, ok := existingHelmVersionCommits[version.Version]
			if !ok || digest != version.Digest {
				hasChanged = true
			}
			if ok {
				versionNumber++
			}
		}
		// if there is a version getting deleted then also set hasChanged to true
		if versionNumber != len(existingHelmVersionCommits) {
			hasChanged = true
		}
		if !hasChanged {
			logrus.Debugf("chart %s has not been changed. Skipping generating templates for it", chart)
			continue
		}

		template := v3.Template{
			ObjectMeta: metav1.ObjectMeta{
				Name: chart,
			},
		}
		template.Spec.Description = metadata[0].Description
		template.Spec.DefaultVersion = metadata[0].Version
		if len(metadata[0].Sources) > 0 {
			template.Spec.ProjectURL = metadata[0].Sources[0]
		}
		iconData, iconFilename, err := helm.Icon(metadata)
		if err != nil {
			errors = append(errors, err)
		}
		template.Spec.Icon = iconData
		template.Spec.IconFilename = iconFilename
		template.Spec.FolderName = chart
		template.Spec.DisplayName = chart
		var versions []v3.TemplateVersionSpec

		for _, version := range metadata {
			v := v3.TemplateVersionSpec{
				Version: version.Version,
			}
			files, err := helm.FetchFiles(version, version.URLs)
			if err != nil {
				errors = append(errors, err)
				continue
			}
			filesToAdd := make(map[string]string)
			for _, file := range files {
				if strings.EqualFold(fmt.Sprintf("%s/%s", chart, "readme.md"), file.Name) {
					v.Readme = file.Contents
				}
				for _, f := range supportedFiles {
					if strings.EqualFold(fmt.Sprintf("%s/%s", chart, f), file.Name) {
						var value catalogYml
						if err := yaml.Unmarshal([]byte(file.Contents), &value); err != nil {
							return nil, nil, nil, nil, err
						}
						v.Questions = value.Questions
						v.RancherVersion = value.RancherVersion
						v.RequiredNamespace = value.Namespace
						for _, category := range value.Categories {
							keywords[category] = struct{}{}
						}
						break
					}
				}
				if strings.EqualFold(fmt.Sprintf("%s/%s", chart, "app-readme.md"), file.Name) {
					v.AppReadme = file.Contents
				}
				filesToAdd[file.Name] = file.Contents
			}
			v.Files = filesToAdd
			v.KubeVersion = version.KubeVersion
			v.Digest = version.Digest
			v.UpgradeVersionLinks = map[string]string{}
			for _, versionSpec := range template.Spec.Versions {
				if showUpgradeLinks(v.Version, versionSpec.Version) {
					version := versionSpec.Version
					v.UpgradeVersionLinks[versionSpec.Version] = fmt.Sprintf("%s-%s", template.Name, version)
				}
			}

			v.ExternalID = fmt.Sprintf("catalog://?catalog=%s&template=%s&version=%s", catalog.Name, template.Spec.FolderName, v.Version)
			versions = append(versions, v)
		}
		var categories []string
		for k := range keywords {
			categories = append(categories, k)
		}
		template.Spec.Categories = categories
		template.Spec.Versions = versions
		template.Spec.CatalogID = catalog.Name
		template.Name = fmt.Sprintf("%s-%s", catalog.Name, template.Spec.FolderName)

		templates = append(templates, template)
	}

	toDeleteChart := []string{}
	for chart := range catalog.Status.HelmVersionCommits {
		if _, ok := index.IndexFile.Entries[chart]; !ok {
			toDeleteChart = append(toDeleteChart, fmt.Sprintf("%s-%s", catalog.Name, chart))
		}
	}
	return templates, toDeleteChart, newHelmVersionCommits, nil, nil
}

var supportedFiles = []string{"catalog.yml", "catalog.yaml", "questions.yml", "questions.yaml"}

type catalogYml struct {
	RancherVersion string        `yaml:"rancher_version,omitempty"`
	Categories     []string      `yaml:"categories,omitempty"`
	Questions      []v3.Question `yaml:"questions,omitempty"`
	Namespace      string        `yaml:"namespace,omitempty"`
}